Toy building block



FIG. 1 is a front perspective view of a toy building block embodying our design;

FIG. 2 is a top plan view of FIG. 1;

FIG. 3 is a bottom view of FIG. 1 with broken lines;

FIG. 4 is a left side view of FIG. 1;

FIG. 5 is a right side view of FIG. 1;

FIG. 6 is a front side view of FIG. 1; and,

FIG. 7 is a back side view of FIG. 1.

The portions of the toy building block shown in broken lines form no part of the claimed design. 

CLAIM We claim the ornamental design for a toy building block, as shown and described. 